On using multiple calibration emitters and their geometric effects for removing sensor position errors in TDOA localization

The use of calibration emitters is known to be able to improve TDOA source localization accuracy when sensor positions are not accurate. This paper derives through CRLB analysis the conditions under which the sensor position errors can be completely eliminated in a source location estimate via deploying multiple calibration emitters whose positions can be erroneous. The implications on the geometric arrangements of calibration emitters to satisfy the conditions are elaborated. In particular, to fully remove the effect of sensor position errors, we need a sufficient number of calibration emitters and they together cannot lie in the same plane with any sensor. The theoretical developments are supported by simulations.